Pneumatic apparatus.



- J. SGHWERTNBR.

PNEUMATIC APPARATUS. APPLICATION nun; MAR.12,1910.

PatentedMay 30, 1911.

who;

q vitnaeoca GT2" {)llE-THERD TO JQHN ASPIN- -..II LD TC? LEQPOLD "n". A. H. HEER- Q13 HAEBROUGK HEIGHTS, Iti' 11W My invention relates to improvements in pneumatic apparatus and more especially to pneumetics such as are used in automatic playing musical instrinnonts to control the operation thereof.

In self playing pianos it is customary to provide it pneumatic device for operating each note and a. tracker board and sheet with aperturescorresponding LO the various notes for controlling the operation thereof. Between the tracker and operating pneu natics, however, it is usual to place one or more icontrolling pneumstics for controlling the action of the operating pneumatics responsive to the operation and particular design of the tracker sheet. in most instances these intermediate pneumatics are controlled and operated by means. of suction or a partial vacuum'produced by suitable bellows. in

, organs the action similar except that it is usual to operate the various devices by Wind pressure, that. is, by.blo\ving action rather than by suction. in both instances, however, it is usual to provide pneumatic arrange ments W'i ii an operating membrane and with to bleed hole leading to one side of the membrane in order to allow of an equalization of pressure on that side of the membrane when it is desired to close a valve. Great trouble is experienced with those blood holes, in that they become clogged with dust and dirt, thus preventing them from fulfilling;

their functions and practically rendering the playing devices useless until the holes are cleorvd properly cleared. lhis, at best, is a very tedious process, and in many cases is attendant with great difliculties due to the ii ioccessibility of the parts, the number of valves and pneumatics, and their complex arrangement.

Dneobjectof my invention is to provide mean or automatically cleaning and clear- {peoification Letters Application filed March 12, 1920. Serial No. 548,815. is. I

E SSUED .srrisnsrns.

Patented May 3% w ll.

ing these bleed holes so that the above difliculties and disadvantages are not experienced. 1

A further object of my invention is to provide means which will vary the efiective size the bleed holes so as to render the devices more sensitive While only a minimum oi air or other mediuin'will be'lost therethrougli. I

Further objects, features and advantages will more clearly appear from the detailed description given below taken in connection with the accompanying drawing which forms a part this specification.

In the drawing, Figure 1 is a vertical section oi one form of an intermediate pneumatic valve such as is used in connection with piano players and operated by suction and provided with one form of my improvements. 2 is a similar View of a. valve operated by Wind pressure, such as is used in organs and showing a similar form of my iinproven'icnts. Fig. 3 is a detail section of the parts adjacent the bleed hole talc-en on the line llllfil of Fig.1.

lileferring to Figs. 1 and 3, 1 represents suitable friunmvork embracing; a pneumatic of the class mentioned. 2 designates a duct losing from the tracker which controls the ,;ilaying of the piano or other instruwent. The duct 2 leads to a chamber or spac over the top of which. is spread. a circular nu ilirune 4: of leather or other suitable material. The edges of the membrane are cemented at its edges to the framework and in its center it is secured to a. spindie 5 by suitable securing means (3. Above the membrane l: is a. chamber-or space 7 in which then is produced suction in it well lrnown manner so that the pressure therein will be that atmospheric. The spindie pisses upwardly through an aperture" 8 into chamber & Just above the aperture or valve opening and secured to the spin die 5 is valve closure 10 arranged. to close the opening 8 when the spindle is in its lowermost position and arranged to allow the chambers 7 and 9 to be connected by the opening 8 when the val e closure is raised by the spindle 5. The spindle 5 passes upas a bearing and guide for the moving'spin i dle 5. From the chamber 9 is a duct lb which leads to the operating pneumatic for the corresponding note. At 1 1 l have shown in dotted lines an old "form of bleed hole.

The operation of the parts so far described is as follow Upon the music sheet opening up the duct 2 to the atmosphere, atmospheric pressure is admitted beneath the membrane 1. Since constant suction is maintained in the chamber 7 this causes the membrane -l to rise and with it the valve closure 10. This allows suction to be produced in the chamber 9 and duct 13 so that the corresponding pneumatic is operated. Upon the closing of the duct 2 to the atmosphere by the tracker sheet the air within the chamber 3 sucked out through the small bleed hole 1-, thus causing the membrane it and spindle to drop and therewith the valve closure and thereby closing the opening 8.

ln practice it is found that the bleed hole 1 1 becomes seriously clogged with dust and dirtwhich is admitted through the duct 1, therefore, omit the bleed hole l-l altogether and provide a chamber 15 below the chamber 3. The chamber 15 is connected with the chamber 7 by a passage 16 and these are so large that dust and dirt will have practically no ellect in stopping up the same. Connecting the chambers 15 and 3 is also a similarly large passage 17, but this passage is very nezirly closed by a brass plate 18 secured to the framework the plate 18 being provided with a small hole 19 therein through which the lower end of the spindle 5 is arranged to move up and down when operating. The lower end of the spindle 5 is reduced or cut away as at 20 and beveled off as at 21. When in its lowermost position the portion 21 is below the plate 18 while when the spindle 5 is in itsnppermos't position as shown in dotted lines the portion 21 is above the plate 1?. 'lhus when the spindle 5 is raised the reduced portion 20 thereof is withi. the bleed hole 19 and the eilective size of tie hole is increased or larger than when th spindl is in its lowermost position.

The operat. in ef the arra.n rement last described is as follows: Whenever the spindle 5 is operated to raise and lower the valve closure 10 the lower end of the spindle 5 works up and down in the bleed hole 19 to keep the same free and clear of dust and dirt, the membrane 9; being withdrawn or drawn downwardly by the suction within the chamber exertin itself through the passage 16, chamber 10 bleed hole 19 and passage 1?. By having the spindle beveled or cut away as at 21 so that it varies in cross sea,

framesection at the part where it operates r1 the bleed hole, it is most efficient for c lug and yet simple, cheap and easy of construction. The larger portions fairly push the dirt out ahead of them. The above arrangenient forms a mostsimple and ell'ectivc automatic means for keeping the bleed hole clear, thus obviating one of the most provoking disadvantages encountered in former arrangements. Furthermore, by increasing the e i'ective size of the bleed hole when the valve is opened the spindle 5 given a much greater impetus at the start when it is desired to close the valve. ln. a similar manner when the valve startstp open the impetus greater because the ellectivc area of the bleed hole is smaller'and less leakage occurs through the bleed hole. .lhat is when the valve starts toopenrthe spindle has a snug tit within hole 1ft except for a most slight leakage, as showninthe drawings. In other words, the bleed hole should have its greatest ell'ective opening when'the spindle is raised in order to return the spindle, quickly when the duct 2 is cl it the bleed hole was made smaller when the spindle was raised it would cause the spindle drop down too slowly and the Li was closed. when the spindle was rais' spindle would never drop back as desired because there would be no way in which to the out from beneath the membrane to allow it to drop and unless the spindle would drop the bleed hole would always remain closed. From the above the great advantage ofalv. "S having the bleed hole open at least having it open when the spindle is raised and with its greatest ellective area when the spindle is raised, will be clearly apparent.

Referring to Fig. 2, l. there show a similar arrangement applied to a valve of the wind pressure variety such as it is customary to use'in organs both of the manual and automatic type. lln this arrangement wind enters from the tracker under pres passes through the duct 22 into the, ohm, ber in the frame 'lhe membr is thereby forced upwardly, thus moving upwardly the spindle 25 whleh 15 secured to ill-5 it. The spindle 26 passes through a brass:

plate 27 and up through a passage 28 and has secured to it a valve closureQf) arranged to close the opening 28 when the spindle 26 is in its lowermost position. Above the passage 28 and valve closure QJisa chamber 30 in which a. suitable wind pressure is constantly produced in a well known manner. Upon the raising of the valve closure 29 by the spindle 26 the wind pressure is admitted to the passage 28 and duct 31 from which it passes to a suitable operating pneumatic to operate the note desired.

In order that the air in the chamber may be allowed to escape and allow the spindle .3

hole absolutely free dust an indicates in dotted lines the old or .ngement 50 tion.

' United States, is:

to drop and close the valve when. the

sure is shut-oft from the duct 22 a passage way 32 18 provided and this pessagewsy 1s covered by a'bress plate having bleed bole 34: therein, through which the excess air in the chamber is allowed to escape to the ntmosphere so that the valve will close. lower portion of the spindle 26 passes through the bleed hole 3% and is reduced at is 35 and beveled at 36 to perform substantially the some functions desc ibed with respect to Figs. 1 and 3. The bleed opening 3st large when the valve closure starts to descend thus dausing the valve to close more '15 quickly. Likewise when starting; upward there is less leakage ab t the spindle 3 thus causing the valve t sen more euickly. Furthermore, the reds. at 35 and bevel at 36 cause the spindle o keep .rc'bleed iirt. 37

of bleedliole in this ind of e which was of great ennoyu sons given. From the above it will e i provide means rig; with the spindl (shown in this particular instance as th -lower portion or" the spindle) which has one or more surfaces at an angle to'tbe line of and rea-

readily seen the movement ofthe spindle." These surfaces are shown as the tapered surfaces 21 and 3b in the drawings and they push the dirt or other foreign matter out the bleed hole wl'icao the pneumatic notion is operated.

These surfaces need not be st'the particular angle shown but should be at a large enough angle to the line o-fsnovernent of the spindle so that they will push the dirt, etc, from the bleed hole. the :spindle is suiliciently 40 well guided in its movement the end or cut away portion 29 ol -tbs spindle may be omitted and the suritace or surfaces 21, 36 will still push the dirt, etc, from the bleed hole. As shown in dotted lines in Figs. 1

and 2, the surfaceslil, 35 come out oi the bleed hole when the valve is o erated in order that they may be in a better'position to force the dirt, etc, from the bleed hole when the action returns to its normal p0si- My improvements may be applied to other valves than those of the kind described wherever the nature of the case will permit. Furthermore, many mod1ficet1ons and changes may be made in the arrangements tied in the appended claims.

Having fully and clearly described my improvements what I claim as new and desire to secure by Letters Fatent oi the l. A. device of the class described, orecrease the effective cross section of the bleed I hole when the valve is opened.

A device of the class described, provided with an operating spindle and membrane and a bleed hole leading to one side of the membrane, said spindle being arranged to operate within the bleed hole to keep the same clear, said spindle being also constructed to vary the effective size of the bleed hole as the device is operated.

8. A. device of the class described, providcd with an operating; spindle and membrane bleed hole lending to one side of membrane, said spindle being erranged to operate within the bleed hole to keep the same clear, ssid spindle being reduced in cross section adjacent the bleed bole to increase the effective size of the bleed bole when the dc ice is opened.

device of the class described, pr0- vided with on operating membrane and spindle, a suitable framework having a suitable space s'bovesnd below the membrane and a bleed hole leading to the space below the membrane, said bleed hole being formed in a metallic plate, said spindle being arranged. to move up and down in said bleed bole to keep the same clear, and said spindle being reduced in cross section adjucent-the bleed hole to increase the effective size of the bleed bole when the device is opened.

5. ln :1 device of theclass described, an operating n'icinbrane, said device being provided with a bleed hole leading to one side of ssid membrane and a spindle having portions thereof operating in said bleed hole to keep the same clear, said portions being of different cross section and the spindle being; always in said bleed hole during the ope z tion of the spindle.

6. In a device of the class described, an operating membrane, said device being provided with e bleed hole leading to one side of said membrane, and a spindle operating in said bleed hole to keep the same clear, said spindle having portions of different cross section, both of said" portions being arranged to operate within said bleed hole. 7, in a. device of the class described, an

operating membrane, said device being provided with s bleed hole leading to one side of said membrane, and e spindleoperating in said bleed hole to keep thesa ne clear, said spindle being tapered at the part. where it operates within the bleed hole.

8. In a device of the class described, a pneumatic action-provided with a bleed. hole,

I I I I and s spindle controlled by said action and operating bleed hole, said 

